Digital control circuit for switching power supply with pattern generator. A method is disclosed for converting DC power from a first voltage level on an input to a different voltage level on an output for delivery to a load. Current from the input is switched to the output through an inductive element with a plurality of switches, each of the switches driven by a waveform, all of the waveforms driving the switches referenced with a predetermined relationship to a master clock and all operating on a PWM duty cycle of the master clock. The voltage/current parameters on the input and output are measured and then a control algorithm is utilized to determine a change in the PWM duty cycle necessary to make a control move, the control algorithm utilizing as inputs the measured voltage/current parameters. A pre-stored waveform pattern for each of the waveforms is then modified to reflect the change in the PWM duty cycle required for the control move. After modification, the modified pattern is output to create the waveform and drive the respective switches.